Using the processing power of computers, it is possible to create a visual reconstruction of a scene or structure from a collection of digital photographs (“photographs”) of the scene. The reconstruction may consist of the various perspectives provided by the photographs coupled with a group of three-dimensional (“3-D”) points computed from the photographs. The 3-D points may be computed by locating common features, such as objects or edges, in a number of the photographs, and using the position, perspective, and visibility or obscurity of the features in each photograph to determine a 3-D position of the feature. The visualization of 3-D points computed for the collection of photographs is referred to as a “3-D point cloud.” For example, given a collection of photographs of a cathedral from several points of view, a 3-D point cloud may be computed that represents the cathedral's geometry. The 3-D point cloud may be utilized to enhance the visualization of the cathedral's structure when viewing the various photographs in the collection.
Current applications may allow a user to navigate a visual reconstruction by moving from one photograph to nearby photographs within the view. For example, to move to a nearby photograph, the user may select a highlighted outline or “quad” representing the nearby photograph within the view. This may result in the view of the scene and accompanying structures being changed to the perspective of the camera position, or “pose,” corresponding to the selected photograph in reference to the 3-D point cloud. This form of navigation is referred to as “local navigation.”
Local navigation, however, may be challenging for a user. First, photographs that are not locally accessible or shown as a quad within the view may be difficult to discover. Second, after exploring a reconstruction, the user may not retain an understanding of the environment or spatial context of the captured scene. For example, the user may not appreciate the size of a structure captured in the reconstruction or have a sense of which aspects of the overall scene have been explored. Furthermore, since the photographs likely do not sample the scene at a regular rate, a local navigation from one photograph to the next may result in a small spatial move or a large one, with the difference not being easily discernable by the user. This ambiguity may further reduce the ability of the user to track the global position and orientation of the current view of the reconstruction.
It is with respect to these considerations and others that the disclosure made herein is presented.